U.S. patent application number 11/428062 was filed with the patent office on 2007-01-11 for vacuum cleaner providing filter-absence detection.
Invention is credited to Ross Richardson.
Application Number | 20070006417 11/428062 |
Document ID | / |
Family ID | 34896921 |
Filed Date | 2007-01-11 |
United States Patent
Application |
20070006417 |
Kind Code |
A1 |
Richardson; Ross |
January 11, 2007 |
Vacuum Cleaner Providing Filter-Absence Detection
Abstract
A vacuum cleaner having a filter assembly 12 disposed on grill
16 between the bag chamber 7 and motor chamber 13. Bag chamber 7
has a cover 8. Filter assembly 12 has an upstanding wall 15
provided with a covering of resilient material, e.g. rubber. The
cover 8 is formed with a grill 14 in a lower region. When the
filter assembly is correctly installed, and the cover 8 is in
position, the resilient covering of the upstanding wall 15 rests in
sealing contact against the inner surface of the cover 8 and over
the grill 14. If the filter assembly 12 is absent, the grill 14
provides direct fluid communication between the bag chamber 7 and
the atmosphere. The cleaner will be ineffective in picking up dirt
thereby alerting the user to the absence of the filter
assembly.
Inventors: |
Richardson; Ross;
(Auchterarder, GB) |
Correspondence
Address: |
GORDON & JACOBSON, P.C.
60 LONG RIDGE ROAD
SUITE 407
STAMFORD
CT
06902
US
|
Family ID: |
34896921 |
Appl. No.: |
11/428062 |
Filed: |
June 30, 2006 |
Current U.S.
Class: |
15/347 ;
15/351 |
Current CPC
Class: |
A47L 9/1472 20130101;
A47L 9/122 20130101 |
Class at
Publication: |
015/347 ;
015/351 |
International
Class: |
A47L 9/10 20060101
A47L009/10 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 7, 2005 |
GB |
0514014.0 |
Claims
1. A vacuum cleaner comprising: at least one aperture defining an
airflow path in fluid communication with ambient for suction of
ambient air; and a removable filter assembly arranged to occlude
said at least one aperture.
2. A vacuum cleaner according to claim 1, wherein: said at least
one aperture is arranged so that, in the absence of said filter
assembly, the majority of the airflow entering into the vacuum
cleaner does so through said at least one aperture.
3. A vacuum cleaner according to claim 1, further comprising: a
main separation stage and a suction fan having an inlet, wherein
the filter assembly is located to provide a filtration stage
between the main separation stage and the inlet of the suction
fan.
4. A vacuum cleaner according to claim 3, wherein: the main
separation stage comprises a separator, disposed in a chamber to
which the suction fan applies suction.
5. A vacuum cleaner according to claim 4, wherein: the separator
comprises a filter bag.
6. A vacuum cleaner according to claim 1, wherein: the removable
filter assembly comprises a filter element supported by a
supporting structure, wherein part of the supporting structure
occludes said at least one aperture.
7. A vacuum cleaner according to claim 6, wherein: the part of the
support structure which occludes said at least one aperture
comprises a projecting part of the filter assembly.
8. A vacuum cleaner according to claim 7, wherein: the projecting
part fits sealingly into, or seats sealingly over, said at least
one aperture.
9. A vacuum cleaner according to claim 1, wherein: said at least
one aperture is formed in a wall of a chamber that has a separator
disposed therein.
10. A vacuum cleaner according to claim 9, wherein: said at least
one aperture is formed in a detachable or hinged cover of said
chamber.
11. A vacuum cleaner according to claim 1, wherein: said at least
one aperture is provided by a grill comprising an array of
openings.
12. A vacuum cleaner according to claim 1, wherein: the removable
filter assembly is removably disposed within the cleaner so that
when installed air passes through the removable filter assembly as
it passes from a suction nozzle or other such inlet and along an
internal conduit of the cleaner, and when removed air is drawn from
ambient through said at least one aperture instead of being drawn
from the suction nozzle or other such inlet and along said internal
conduit.
13. A filter assembly for a vacuum cleaner having least one
aperture defining an airflow path in fluid communication with
ambient for suction of ambient air, the filter assembly comprising
a filter element for airflow passing therethrough, and a part
arranged to occlude said at least one aperture.
14. A filter assembly according to claim 13, wherein said part of
the filter assembly is provided with a sealing means for sealing
around said at least one aperture.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a vacuum cleaner and more
particularly to a vacuum cleaner which enables the user to detect
when a filter unit of the cleaner is absent.
[0003] 2. State of the Art
[0004] Modern vacuum cleaners generally operate on a "clean-air
fan" principle, according to which the airflow through the cleaner
is created by a fan located in the airstream at a point downstream
of the separator arrangement which removes dirt and dust from the
incoming suction airflow. Dirty air is drawn into the cleaner
through a floor-engaging nozzle or other suction inlet and passes
through a conduit to the separator arrangement, connected in fluid
communication with the inlet of the fan. The airflow thus passes
through the separator arrangement and the fan, and is then expelled
from the cleaner, to ambient, through an exhaust outlet. The
separator arrangement may take any one of several forms, of which
filter bags and cyclone separators are the most common, although
other arrangements including rigid porous dirt containers are also
known. In conventional vacuum cleaner fan systems, the fan and the
electric motor which drives the fan are integrated into a compact
unit in which the air leaving the fan passes over the motor to
effect cooling of the motor. It will be appreciated that should the
separator arrangement fail effectively to remove dirt and
impurities from the airflow before this airflow reaches the fan,
then this dirt could cause damage to the fan and its motor. For
this reason it is conventional to provide an additional stage of
filtration between the separator arrangement and the inlet to the
fan, this additional filtration stage generally being known as the
pre-motor filter.
[0005] Since pre-motor filters must be removed from the cleaner
periodically for cleaning or renewal, it will be appreciated that
situations can arise where the user operates the cleaner with the
pre-motor filter absent. This is clearly undesirable, and a number
of arrangements have been proposed hitherto for preventing the
occurrence of such situations. For example, European patent
application EP 0,895,744 discloses an arrangement in which the
presence of the pre-motor filter is detected by an electronic
scanning system: an electronic sensing device is mounted on the
body of the vacuum cleaner and co-operates with a sensing element
attached to the filter to produce a signal dependent on the
presence or absence of the filter, or indeed on the presence of the
correct type of filter and/or its correct installation in the
cleaner; the signal may be used to initiate a filter-absent warning
to the user and/or to prevent the fan motor from starting. This
filter-presence detection system is complicated and is expensive to
manufacture, rendering it unsuitable for simple low-cost
products.
[0006] A number of other detection systems have been proposed, for
detecting the presence or absence of the pre-motor filter, based on
the principle of preventing the use of the cleaner unless the cover
which closes the separation chamber is correctly installed. A
typical arrangement of this type is disclosed in European patent
application EP 1,214,903, in which correct installation of the
filter results in a spring-loaded tongue being withdrawn from a
position in which it would obstruct closure of the dirt receptacle:
without the dirt receptacle being properly closed, the cleaner
cannot function. This and other mechanical arrangements are
generally complicated and increase the manufacturing costs
unduly.
SUMMARY OF THE INVENTION
[0007] We have now devised arrangements which are of simple and
inexpensive construction, for indicating to the user when a filter
of the cleaner is absent and preventing the cleaner from being used
with the filter absent, whilst maintaining a flow of clean air over
the fan motor to effect cooling.
[0008] In accordance with the present invention, there is provided
a vacuum cleaner which includes a filter assembly or unit arranged
for a part thereof to occlude at least one aperture provided in the
structure of the cleaner and through which, in the absence of the
filter assembly or unit, the suction airflow path of the cleaner is
in fluid communication with ambient.
[0009] In use of this vacuum cleaner, should the filter assembly or
unit be absent, air is drawn in from ambient through the at least
one aperture, rather than along the suction path from the suction
nozzle or other suction inlet of the cleaner. The cleaner is thus
ineffective in picking up dirt through the suction inlet and this
situation is immediately apparent to the user, and must be remedied
by replacing the filter assembly.
[0010] Preferably said at least one aperture is arranged (typically
as a result of the dimensions of the aperture or apertures and of
its location) so that, in the absence of said filter assembly, the
majority of the suction airflow entering the cleaner does so
through said at least one aperture.
[0011] Preferably the filter assembly is located to provide a
filtration stage between the main separation stage of the cleaner
and the inlet to the suction fan. The main separation stage
comprises a separator, typically in the form of a filter bag,
disposed in a chamber to which the fan applies a suction.
[0012] The filter assembly preferably comprises a filter element
mounted to or in a supporting structure (for example in the form of
an open frame) a part of which forms the part of the assembly which
occludes said at least one aperture in the structure of the
cleaner, when the filter assembly is installed in the cleaner.
Preferably said part of the filter supporting structure comprises a
projecting part of that structure. Preferably this projecting part
fits sealingly into, or seats sealingly over, said at least one
aperture.
[0013] Preferably said at least one aperture is formed in a wall of
the chamber in which the filter bag or other separator unit is
disposed, and is preferably formed in a detachable or hinged cover
of that chamber.
[0014] Preferably said at least one aperture is provided by a grill
which comprises an array of openings.
[0015] In an embodiment which will be described herein, the filter
assembly is removably disposed within the cleaner across the
suction airflow path therethrough, for the air to pass through the
filter as it passes along an internal conduit of the cleaner: said
at least one aperture is formed through the structure of the
cleaner, to ambient, adjacent the filter assembly, so that should
the filter assembly be absent, air is drawn in from ambient through
said at least one aperture, instead of being drawn into the cleaner
from a suction nozzle or other suction inlet and along said
conduit.
[0016] Also in accordance with the present invention, there is
provided a filter assembly for a vacuum cleaner, the filter
assembly comprising a filter element for the suction airflow to
pass through, and a part arranged to occlude at least one aperture
formed in the structure of the cleaner and communicating with
ambient. Preferably said part of the filter assembly is provided
with a sealing means for sealing against said structure of the
cleaner, around said at least one aperture.
[0017] An embodiment of the present invention will now be described
by way of example only and with reference to the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a schematic view of a prior art vacuum cleaner of
the upright type;
[0019] FIG. 2 is a schematic sectional view of the lower region of
the bag chamber of an upright vacuum cleaner in accordance with the
present invention, and shown with the pre-motor filter unit
present:
[0020] FIG. 3 is a similar view of the lower region of the bag
chamber, shown with the pre-motor filter absent; and
[0021] FIG. 4 is an exploded view of the main housing of an upright
vacuum cleaner in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMODIMENTS
[0022] Referring firstly to FIG. 1 of the drawings, there is shown
a conventional vacuum cleaner of the upright type, comprising a
floor-engaging foot or base unit 1 to which an upright body 2 is
pivotally mounted. The floor-engaging unit 1 is provided on its
underside with a suction mouth or inlet 4 in which a rotating brush
5 is disposed. The upright body 2 comprises a housing which is
divided into two chambers, namely the bag chamber 7 which is closed
by a removable cover 8 and, in use, encloses a porous filter bag 9,
and a motor chamber 13 in which a motor/fan unit 6 is mounted.
[0023] The motor chamber 13 is divided into two separate regions,
one in fluid communication with the bag chamber 7 via a grill 16,
and the other in fluid communication with an exhaust-air outlet 11.
The grill 16 comprises a wall or partition formed with an array of
openings and, in the example shown, effectively forms the floor of
the bag chamber 7 and supports a filter element 12 which is
disposed on the upper or upstream side of the grill 16.
[0024] In operation, the motor/fan unit 6 applies suction to the
bag chamber 7, generating an airflow from the bag chamber 7 and out
through the exhaust outlet 11. The resulting negative pressure in
the bag chamber 7 gives rise to a flow of air from the suction
inlet 4 to the interior of the bag 9 via a duct 10. Having passed
through the filter bag 9, the clean air passes through the
pre-motor filter 12 and enters the motor chamber 13 by way of the
grill 16.
[0025] Referring now to FIG. 2 of the drawings, a vacuum cleaner in
accordance with the present invention corresponds with the
above-described cleaner of FIG. 1 but with the following
modification. Thus, the pre-motor filter comprises an assembly 12
of generally planar form, supported on the grill 16, but having an
upstanding wall 15 extending along its forward edge. The front
surface of the upstanding wall 15 is provided with a covering of
resilient material for seating against the inner surface of the bag
chamber cover 8, when the filter assembly is correctly installed
and the cover 8 is fitted to close the bag chamber. The cover 8 is
formed, in a lower region thereof, with a grill 14 the apertures
through which are occluded by the upstanding wall 15 of the filter
assembly 12, the covering of resilient material on the upstanding
wall 15 serving to seal against the cover 8 around the periphery of
the grill 14. It will be appreciated that when the filter assembly
12 is correctly installed and the cover 8 is closed, as shown in
FIG. 2, then the fan creates an airflow in the cleaner, indicated
by the arrow A in FIG. 2, which leaves the filter bag 9, passes
through the pre-motor filter assembly 12 and enters the motor
chamber 13 through the grill 16.
[0026] Should however the filter assembly 12 be absent from the
cleaner, as shown in FIG. 3, then the bag chamber 7 will be in
direct fluid communication with the atmosphere by way of the grill
14 of the bag chamber cover 8. It will be appreciated that, in this
situation, the fan will draw in air from the exterior of the
cleaner, through the grill 14 of the cover 8, and directly into the
motor chamber 13, as indicated by the arrow B in FIG. 3. The bag
chamber 7 will not be evacuated or subjected to any significant
suction and no flow of air will occur from the floor-engaging
suction inlet or nozzle of the cleaner: the cleaner will therefore
be ineffective in picking up dirt. This condition will immediately
be apparent to the user, who can then remedy it by replacing the
filter assembly. Whilst the filter assembly is absent from the
cleaner, only clean air is drawn into the motor chamber 13, over
the path B, so avoiding potential damage to the motor/fan unit.
[0027] FIG. 4 is a more detailed view, in exploded form, of the
main housing of the cleaner in accordance with the present
invention. It will be noted that the filter assembly 12 comprises a
planar filter element 17, typically of foamed plastics material or
a pleated polyethylene sheet, fixed into a frame member 18 of
plastics material which, in use, rests on the grill 16 which forms
the floor of the bag chamber 7. The upstanding wall 15 of the
filter assembly is formed integrally with the frame 18 and its
outer surface carries a pad 19 of resilient material, typically
soft rubber. The filter element 17, frame 18 with upstanding wall
15 and resilient pad 19 thus form the filter assembly 12, which is
removable as a unit from the cleaner for cleaning or renewal. It
will be appreciated that when the filter assembly 12 is correctly
installed and the cover 8 is in position closing the bag chamber 7,
then the resilient pad 19 will rest in sealing contact against the
inner surface of the cover 8, over the grill 14 formed in the lower
region of the cover. Should the filter assembly be absent, the
grill 14 will provide direct fluid communication between the bag
chamber 7 and the atmosphere surrounding the cleaner, and negative
pressure in the bag chamber, essential for effective operation of
the cleaner, will not be set up.
[0028] In the embodiment shown in FIG. 4, the bag chamber cover 8
extends below the level of the floor of the bag chamber 7 and is
formed with a second grill 20, below the grill 14: the grill 20 is
however provided for aesthetic reasons only. Two ribs 21 may be
provided, as shown, projecting upwards from the grill 16 of the bag
chamber, for locating the filter assembly where this is modified to
co-operate with such ribs.
[0029] It will be appreciated that the above-described vacuum
cleaner incorporates a simple and inexpensive arrangement for
providing a clear indication to the user in the event that the
filter assembly being absent and accordingly preventing the fan and
motor from being damaged by incoming dirt.
* * * * *